COTTON IN EGYPT AND THE SUDAN. <>9 



very rapidly over the whole plant. When the caterpillars are very 

 numerous they attack also the buds. These insects attack cotton 

 from end of April to end of September, and are most injurious in the 

 months of June, July, and August ; they do not appear simultaneously 

 everywhere but only locally, one year in this, the other in that dis- 

 trict ; they chiefly appear in the Delta, particularly in the northern 

 parts. Where the worm is present early in summer the plant has time 

 to recuperate from its attacks, although quality and quantity of the 

 lint suffer from its effects. The damage is, however, much greater 

 when the worm makes its appearance at a later period of the develop- 

 ment of the plant. In any case, a plant once attacked by the worm is 

 weakened and its growth is affected, therefore it is more liable to 

 be attacked by the more dangerous boll-worm, which appears only 

 comparatively 'late in the season. In 1904 the cotton worm caused 

 a damage of ^200,000, and in some provinces a third or even half 

 of the cotton fields were infested by it; in 1910 643,000 feddans were 

 attacked by the cotton-worm, and of this area only 6,000 feddans 

 were situated in Upper Egypt. 



Outside of Egypt, Prodenia is not known to cause any serious 

 damage, rjtobably because it is kept in check by other insects, and 

 the Agriculture Department therefore endeavours to introduce such 

 insects from abroad ; some such enemies of the Prodenia are already 

 in existence in Egypt. Besides this the only really effective remedy 

 against the cotton worm is, so far, either to pick from the Berseem 

 the eggs and caterpillars or tear off and burn those leaves of the 

 cotton plant \vhich have been infected by the cotton-worm, and as 

 the numerous eggs are always met with on a few leaves only it is 

 comparatively easy to remove them. 



The opinion expressed in various books to the effect that the 

 eggs are met with only on the lower leaves of the cotton plant is 

 not correct ; they are also found in the middle and upper portions of 

 the plants. Fields of berseem which are severely infested by the 

 cotton-worm should be mown and ploughed under before the worm is 

 able to penetrate into the cotton fields. But the ploughing by means 

 of the Egyptian plough is not sufficiently effective, and therefore 

 it is better to flood such fields which are severely infested by the 

 cotton-worm. 



Earias insulana, known in Egypt under the name of boll-worm, 

 is much more difficult to keep in check, and the damage caused by 

 it is much more considerable ; it has been met with everywhere 

 annually, and has been described in Egypt as far back as 1865. The 

 small butterfly, w r hich has a length of only 9 mm., is easily recog- 

 nised by its green fore wings and its silvery white dark-bordered 

 hind wings ; it lays its very small bluish-green eggs from the begin- 

 ning of August outside the bolls or on the flower buds, the young 

 caterpillars w r hich come from these eggs penetrate in most cases 

 first the young shoots, later on the young buds and the young bolls ; 

 they feed on their contents, especially on the soft, juicy seed kernels, 

 and then they attack other bolls. Young bolls dry up in consequence 

 of these attacks and die, more developed bolls open in consequence 

 of the attack prematurely, and their fibre does not mature. As the 

 caterpillars slip out of the eg^s three or four days after they have 

 been deposited, form a chrysalis 15 or 20 days later, and the butter- 



